1. Field
Embodiments of the invention relate generally to the field of oscillator circuits. More particularly, an embodiment of the invention relates to an improved architecture for a compensating crystal oscillator.
2. Description of the Related Art
Wireless portable technology has become a necessity in today's environment. Hence, many persons throughout the world own or use a cellular telephone and/or wireless device that needs to connect to a base transmitter station.
In connecting a wireless device or handset to a base station, the frequency of the connection signal of the handset or wireless device is synchronized to the broadcast signal of the base station. Therefore, the wireless device generates a frequency approximately equal to the frequency of the base station. To generate the frequency, a wireless device contains an oscillator.
Some oscillators currently used by wireless devices are Voltage Controlled Temperature Compensated Crystal Oscillators (VCTCXO). Crystals are good piezoelectric materials for creating an oscillator circuit, but because of temperature changes to the device, the material may create a frequency deviation in the oscillation. Therefore, the oscillator circuit is compensated for deviation from the desired frequency. Even though a simple crystal combined with oscillator circuitry is much cheaper than VCTCXO's, a simple crystal combined with oscillator circuitry alone is not accurate enough for wireless communications because of the frequency deviations. Hence, a VCTCXO may be used by most device manufacturers, such as, but not limited to, Motorola®, Ericsson®, Nokia®, and Audiovoxx®.
A VCTCXO is a pre-packaged component that compensates for frequency deviation due to temperature change such that a high level of accuracy needed for wireless communications can be achieved.
One problem with using a pre-packaged VCTCXO is that the component can be relatively expensive. Another problem with using a pre-packaged VCTCXO is that extra space in the wireless device is dedicated to the component. Because of the shrinking form factor of each generation of wireless device and the expanding quantity of production of wireless devices, a solution is needed in lowering the cost of production and minimizing the form factor of a wireless device.